1. Technical Field
Aspects of the exemplary embodiments relate to a breast pump which can express milk by an operation unit that can be manually or mechanically driven.
2. Related Art
A related art breast pump includes a milking part that is diameter-expanded in the shape of a trumpet and is brought into contact with a mother's breast, that is, a diameter-expanded milking part.
Particularly, a related art breast pump is constructed such that a recess is provided at the upper end of a breast pump body to prevent milk that has been expressed as a mist due to a negative pressure during milking from leaking to the outside, and a deformable member such as a diaphragm is housed in this recess.
Namely, in a manually operated related art breast pump disclosed in U.S. Pat. No. 5,749,850, an operation unit such as a handle is connected to the diaphragm, and the diaphragm is repeatedly pulled up by reciprocation of the handle to create a negative pressure.
Some related art breast pumps having substantially common components with those of the above-described related art breast pump are disclosed in U.S. Pat. No. 6,749,582 and International Publication Nos. WO2003/013628 and WO2004/000390.
Further, in another related art breast pump, a recess part is provided on a handle side, and a diaphragm is housed in this recess part, whereby a negative pressure is transmitted through a vent path of a breast pump body side into the breast pump body, as disclosed in US Patent Application Publication No. 2004/039330.
Further, in a related art breast pump described in U.S. Pat. No. 5,009,638, a cylinder is arranged at the upper portion of a breast pump body, and a cup-shaped diaphragm is set to the cylinder to make the cylinder airtight, whereby the diaphragm is deformed by a negative pressure by a machine and its deformation puts the inside of the breast pump body in a state of the negative pressure.
However, in these related art breast pumps, the mother's milk that has flown backward and the mist of milk can enter the recess or the recess part in which the deformable member such as the diaphragm is housed.
On the other hand, since the related art breast pump is used to express milk to be given to a baby, if the milk has entered the recess or the recess part, it is necessary to wash the recess or the recess part readily and cleanly after the milking operation in order to use the breast pump cleanly.
Further, in the above-mentioned related art breast pumps, in case that the mist of milk has entered the diaphragm housing part, because the housing part is formed of hard resin, the mist of milk and the residue of milk that have entered small gap are difficult to remove. Therefore, the related art breast pumps cannot be always used cleanly.